AVS 46th International Symposium
    Magnetic Interfaces and Nanostructures Technical Group Thursday Sessions
       Session MI+NS-ThA

Paper MI+NS-ThA4
Magnetic Imaging by Spin-polarized Scanning Tunneling Microscopy

Thursday, October 28, 1999, 3:00 pm, Room 618/619

Session: Magnetic Imaging
Presenter: W. Wulfhekel, MPI fur Mikrostrukturphysik Halle, Germany
Authors: W. Wulfhekel, MPI fur Mikrostrukturphysik Halle, Germany
J. Kirschner, MPI fur Mikrostrukturphysik Halle, Germany
Correspondent: Click to Email
A new approach to spin-polarized scanning tunneling microscopy based on the magneto tunnel effect between a ferromagnetic tip and a ferromagnetic sample is demonstrated. By periodically changing the magnetization of the tip in combination with a lock-in technique, topographic and spin-dependent parts of the tunnel current are separated. This allows to simultaneously record the topography and the magnetic structure of the sample. First results are given for polycrystalline Ni and single crystalline Co(0001) surfaces, revealing a high spin contrast of up to 20% of the tunneling current, low data acquisition times of few ms/pixel and a resolution down to 10nm. The magnetic origin of the observed signal is proven rigorously by recording the domain wall motion due to an applied magnetic field during scanning. Potentials and limitations of this new technique are discussed.